Sanding and polishing machine shoe



Nov. 15, 1949 E. G. PETERSON smnme AND rousnme MACHINE snon 2 Sheets-Sheet 1 Filed May 24, 1946 INVENTOR.

Edward Cij eieraam Nov. 15, 1949 E. s. PETERSON 2,488,098

SANDING AND POLISHING MACHINE SHOE Filed May 24, 1946 2 Sheets-Sheet 2 JNVENTOR.

Patented Nov. 15, 1949 {SANDING AND POLISHING MACHINESHQE Edward G. Peterson, Rockford, 111.; lAnna' Peter- .son executrix ofsaid Edward'G.Pet erson,{de-

ceased Application May24, 1946,;Serial-No.:o72,123

14fClaims.

Thisinvention relates to .shoesfor rubbing and polishing machines.

i. It isla general object of the invention to provide such'a shoe orpadforsuDDOrting sheets of rubbing material, the shoe being detachably mounted upon thereciprocatinghead:of: such machine.

1'Further.zobq'ects:v ofumy: invention are to providea' new. and improved shoe for supporting a sheet orsheets of: abrasive. orother rubbing material; .to provide .aJneW and improved; pad for application to awreciprocatingxdevice. andwhich provides a cushion-like backing for. sandpaper or other materialsstretched.thereover; to provide a yieldable padwhichnwill .providean efficient backing for sandpaper or other rubbing material. when usedagainst curved..sur faces; .to provide a pad embodying a metal plate with attaching devices eXtendingtherefrom, ansheetof' rubber on the plate, a pad of spongerubber and-za:sheet of rubber enclosing the sponge rubber t-and vulcanized to the rubber sheet ion-the plate; to provide a supporting plate andnovelumeans for detachably securing the pad tothe plate tointroduce air under pressure into :.the. pores :of .a. sponge rubber shoe while vulcanizing the rubberpartstogather in a heated. mold and to relievei the; air pressure'irom the shoe pores after the vulcanizing operation is completed and to permit said pores to contain air under: atmospheric pressure, :and then-sealing said pad against the escape or. entry of air'the'r efrom or thereto.

Other objects win. become readily apparent from the following detailed description taken in connection with the accompanyingdrawings in which:

Fig. 1 is a plan in reduced sizeof the top face of a rubbing shoe embodying my invention.

Fig. 2 is a side edge elevation of the rubbing shoe of'Fig. 1.

Fig. 3 is a top face view, on a larger scalethan that of Fig. 1, of thepad and showing .fragmentarily a sheet of rubber-like material secured fiatwise to the bottom face thereof before the addition thereto of the other .parts of the shoe.

Fig.4 is a side edge elevation ofFig. 3.

Fig. 5 is an exploded side edge View, partly. in section, of an attaching'plate showing a rubber sheet on each side of the plate before being secured thereto.

Fig. 6 is an exploded side edge view of the attaching plate .with the rubber sheets applied thereto, and thepad and its enveloping-sheet spaced therefrom' prior to placing in the vulcanizing mold.

Fig. Us a topplan view of Fig. 6.

2 a Fig. 81s an enlarged fragmentarysection on the m s -a of-Fig. 1. I j f F ig. 9i .is .an; enlarged Iragmentary section -on the line gasp n 1'. Fig-1,0 is anwenlarged centralvertical. section through a Vulcan ingmold, partly open, withthe parts of the rubbing-shoe in position therein prior to being vulcanized together. '7

-.Fig..11 is a view. similar to Fig-.19, but. showing the mold. closed, and. ready for .thevulcanizing operation. Fig. 12 is a perspective.view oi amodified form ofmy rubbing shoe. t V

. Fig. 13.:is a vertical transverse section onthe line l 3l3.of Eig.;1 2. t v while my inven foniurther resides in thecombination,..construction. andarrangement of parts illustrated in the H ccompanying drawimgs I have shown therein .-ior illustrative purposes ;only, a preferred embodiment, and wishinunderstood that the sameds susceptible of modification and change ;without;. departing from the .spirit and scope of the appended claims. 8

Inthe form shoWnin-Figs. 1 1 l ofthe drawings my; invention. comprises a. metal attaching plate I havinga plurality of spaced. upstanding attachmentscrews :2,.fixed.thereto. The plate I :is formed;v with a central. opening 3,: and attached to thelowenfafle of the plateisa sheet 4 of rubberi e m terial a sohaving a open n 5 commun eating =witn open e 3 n hep ate i ee F 5). Eositioned on the top face ofplated isasheetfi of .;1-r1 1bber.-like :ma erial,-jhavin "openin s .DO tioned to pass over theaattachment screws .2 to permit sheet;fi-iclqsely.to. contact plate I. ,Sheet 6*5l'ls0.;has -a..c entra1 openin I which omm n at s with-open n s int-th plate. :Th ed es of sheet 4 "and figexten :aa light. dist nce beyond h iperipheral, dges o 21 311 6 ;and are 1 there vulcanized tos theras seen-inFia- I The plate I-and sheets 4 Sand :6 are shown slightly=zspaced apar rim-Fig. Evior clearness. :As will be explained: later the overlapping edges-10f the rubher sheets i 4 sandwfi will :be vulcanized together around he periphery .of plate Land .will lee-secured: to the opposite facesof, plate I -.by as efiective an. adhesive as is possible. to obtain? for adhesion :between' -..=metal an'd. 'rubberlikejmata rial. .i'FiggzSlShOWS thesevarious'sheets andiplate' I in'xisection' taken onia .transversefcline passing throughr one oftheiattachment screws,.-a'fter.beihg attached to the pad.

' Aseseenin .Fig.;.4,ea .pad'..8 ofspongerubber :or the like issgluedi-orz otherwisetemporarily. secured atits/lowerifaceitdthe .envelopesheet 9 of rubberlike material, the edges of which when in flat position extend a substantial distance beyond the pad. These edges are later bent upwardly around the side and end edges of the pad to overlap the same so that they will be positioned between the lower face of sheet 4 and the pad 8 when pressed in a mold preparatory to vulcanizing these parts together. Pad 8 is likewise provided with a central lateral opening Iii which communicates with openings 5, 3 and 1 described above.

After the plate I and sheets 4 and 6 have been assembled together in the form shown in Figs. and 6, the pad 8 and sheet 9 will be positioned within the cavity II in the bottom half I2 of a mold comprising said bottom half and a top half l3, as shown in Fig. 10, with the end and side edges M of sheet 9 overlapping the top face of the pad. The assembly of sheets and metal plate, as shown in Fig. 10, is then placed over the pad 8 with the central holes in these parts in communication with the hole 10 in the pad. When the parts are in the position shown in Fig. 10 pressure is applied to the top half of the mold by suitable pressure means, and the two halves of the mold are pressed together to the position shown in Fig. 11. The lower flat face of the upper half l3 of the mold bears downwardly against the upper face of sheet 6 to press this sheet into firm contact with the metal plate and hold them thus positioned, screws 2 freely passing into holes a for clearance.

The upper half l3 of the mold is provided with a screw threaded connection l5 connected with a piping l6 leading to any suitable source of air under pressure. 7 provided with a centrally positioned aperture in which is fixed a pipe H which at its lower end passes through the central openings 1, 3 and 5 of the upper sheets and metal plate. of pipe I! preferably extends a slight distance at l8 downwardly into the hole [0 in the pad so thatwhen air under pressure is introduced thereinto it will fill all of the pores in the sponge rubber pad. The upper half I 3 of the mold is provided with intercommunicating passageways l9 through which steam is passed from the inlet' pipe and out through the outlet pipe 2| in order to heat the upper half of the mold to any desired't'emperature. The bottom half l2 of the mold is likewise formed with an interior passageway 22 for steam or other heating mediumsupplied through the inlet pipe 23 and exhausted through the outlet pipe 24.

From the above it is seen that the rubber-like sheets, metal plate, sponge rubber pad and the envelope rubber-like sheet, are assembled and then placed into the mold cavity as shown in Figs. I0 and H. Steam is then (or previously)" introduced at any desired temperature into the cavities l9 and 22 of the mold parts, pressure being applied to clamp the mold parts together under action of suitable pressure means. Air under pressure is then introduced through pipes l6 and I1 into the interior of the pores of the sponge rubber pad 8, which presses and firmly holds the envelope sheet 9 against the mold surface, the edges of this sheet being firmly pressed between sheet 4 and pad 8 as described above, when the mold is closed. The heat of the mold vulcanizes the pad 8 to the envelope sheet 9 and the edges of sheet 4 to the edges of sheet 6 around plate I, and also vulcanizes the sheet 4 to edge portions 14 of the envelope sheet and to any exposed top faceof the pad as will be under- The upper half of the mold is This end stood in Fig. 11. In order to prevent escape of air upwardly along the outside of pipe I! a metal washer w is nonleakably fixed to the outside of pipe I! (see Figs. 10 and 11). The hole 5 in the rubber-like sheet 4 (see Fig. 5) is of substantially smaller diameter than that of the washer w so that when air pressure is introduced into the sponge rubber pad 8 this pressure will force the rubber-like material directly below the washer tightly against the lower face of the washer and prevent leakage of air upwardly around the outside of pipe H.

In carrying out this invention I have accomplished satisfactory results by applying an air pressure of about pounds per square inch inside of the pad 8, at the same time heating the adjacent faces of the mold parts with steam at 45 pounds steam pressure. This is continued for a period of about one hour during which the vulcanization of these parts takes place. The air pressure applied during vulcanization ensures a smooth surface on the outside of the shoe pad and prevents the rubber-like material of the envelope sheet 9 from curling and appearing wrinkly.

When the vulcanization is complete the air pressure within the pad 8 is released so that air under atmospheric pressure is present within the pores of the pad. The mold parts are then separated and the shoe is removed from the mold, after which the opening I in the upper sheet 6 is sealed shut by any desired means such as a rubber plug, rubber disk or the like 25 vulcanized or otherwise secured in an air-tight manner thereto. The presence of air under atmospheric pressure in the pores of the pad is helpful in supporting sandpaper or the like working on curved contours for the reason that pressure against one portion of the pad slightly expands the remainder of the pad.

The important feature of the pad is its ability to be used on a reciprocating tool. This success is due partly to the manner in which the pad is secured to the metal plate and the use of sponge rubber in the casing instead of the mere inflation of a bag. The sponge rubber gives support to the rubber cover and causes the bottom surface to move substantially the full stroke of the machine. In addition, it eliminates the need for pressure within the casing and the disadvantage of such pressure which would bulge the bottom of the shoe in the middle.

Successful results have been obtained by using neoprene for the rubber sheets, but any other suitable rubber-like material which is adapted to the purposes intended may be used. Also other suitable material could be substituted for the sponge rubber material.

As will be understood, the rubbing shoe of the present invention may be detachably secured to the actuator of a reciprocating device by passing the screws 2 through complemental holes in said actuator and applying nuts thereto.

In the form shown in Figs. 12 and 13 the arrangement of parts is similar to that of Figs. 1-11 except that the metal plate I is omitted, the top sheet 6' is formed of thicker and wider rubber than sheet 6, with a thin sheet 4 vulcanized between the sheet 6 and the envelope sheet 9'. Sheet 4' is of less width than sheet 6' so that the latterhas overhanging edges 26 to be seated in the recesses of the angle strips 21 which are each along the lower edge formed with an inwardly extending flange 28. Strips 21 are fixed in anyv desired manner to the reciprocating head 29 along the outer edgeof the lower face as seen in Fig, 1-3. ,Head 29 is arigidmetalplate mounted for reciprocation in a rubbing machine" (not shown). It will thus be seen that due to their resiliencythe overhanging-edges 26-of sheet 6' maybeforced into the recesses above flanges 28 for attaching the rubber shoe-to the head plate 29, and removed therefrom when desired to remove: the shoe from thehead. In Figs. 12 and 13 the parts will be assembled and vulcanized in amanner and mold similarto that described in connection with Figs. 1-11.

- .In both forms of my invention one or .more sheets 36- ,of sandpaper, emery cloth, or other treating or polishing material, will be laid over the bottom face of the pad, extended up and over the ends thereof and removably securely gripped or clamped between clamping plates 3|. Rubber plug, disk or the like 25' in Fig. 13 corresponds to the similar part 25 in Figs. 6 and 9.

I claim:

1. A rubbing and polishing shoe comprising, a metal plate, a sheet of covering material on the bottom face of said plate, a resilient pad below said sheet of covering material, and a sheet of flexible material coverin the bottom face andside and end edges of said pad, and being secured to said first mentioned sheet, said pad being porous and having air sealed in the pores against escape therefrom.

2. A rubbing and polishing shoe comprising, a metal plate, a sheet of covering material on the bottom face of said plate, a resilient pad below said sheet of covering material, and a sheet of flexible material covering the bottom face and side and end edges of said pad, and being secured to said first mentioned sheet between it and the top of the pad, and a plurality of attaching devices secured to said plate, said pad being porous and having air sealed in the pores against escape therefrom.

3. A rubbing and polishing shoe comprising, a metal plate, a sheet of covering material on each face of said plate, a resilient pad, and a sheet of flexible material covering the face and side and end edges of said pad, said sheet of flexible material having its ed e portions secured between the pad and one of the first mentioned sheets, all of said sheets being formed of rubber-like material.

4. A rubbing and polishing shoe comprising, a metal plate, a sheet of covering material on each face of said plate, a resilient pad, and a sheet of flexible material covering the face and side and end edges of said pad, said sheet of flexible material having its edge portions secured between the pad and one of the first mentioned sheets, all of said sheets being formed of rubber-like material, and said pad being formed of sponge rubber and the like.

5. A rubbing and polishing shoe comprising, a metal plate, a sheet of covering material on each face of said plate, a resilient pad, and a sheet of flexible material covering the face and side and end edges of said pad, said sheet of flexible material having its edge portions secured between the pad and one of the first mentioned sheets, said sheets being formed of rubber-like material, and said pad being formed of sponge rubber and the like, the pores of said sponge rubber pad containing air under atmospheric pressure, both of said sheets of covering material and said metal plate having registering openings leading to the interior of the pad, and a closure for said openlugs to prevent escape of said air from'the pad.

6.. Arubbing and polishing shoe; comp n ii metal plate, a sheet of covering. material on: one face of ,said plate, a, porous "resilient pad onvthe same-face of saidplate-,;, and asheet of, rubber-like material covering theface. and side and end edges of said pa'd,,said sheet of 'rubber-l-ikematerial beingsecured tosaid firstmentioned sheet and said sheets retaining air-within the pores of said pad.

7. A rubbing and, polishing shoe comprising,,a metal; plate, a. sheet of covering material on: each face of saidgplate, a; resilient porous pad and. a sheet of rubber-like material coveringthebottom and side and-end edges of said pad, said sheet of rubber-like material being secured to one of said first mentioned sheets, and a plurality of attaching devices secured to said plate and projecting through one of said firstmentioned sheets, said attaching devices being in the form of spaced,

apart threaded studs, and said sheets sealing air against escape from the pores of said pad.

8. A rubbing shoe adapted to be detachably secured to the reciprocating actuator of a rubbing machine, comprising a metal plate having spaced apart attaching devices secured thereto and projecting from one side face thereof, a sheet of rubber-like covering material on one face of said plate, said attaching devices protruding through said sheet, a pad of sponge rubber and the like on the other side of the plate, a sheet of rubber-like material covering the face and side and end edges of the pad, and means for securing said last mentioned sheet to the plate.

9. A rubbing shoe as claimed in claim 8, in which the sheet covering the pad is vulcanized to the pad where it contacts the same.

10. A rubbing shoe as claimed in claim 8, in which there is air in the pores of the sponge rubber of the .pad, said air being retained in the pores of the pad by said sheets.

11. A rubbing shoe as claimed in claim 8, said plate and the first mentioned sheet having registering openings communicating with the sponge rubber pad, and a seal for the opening in the first mentioned sheet to prevent escape of air from the pad through said openings.

12. A rubbing shoe adapted to be detachably secured to the reciprocating actuator of a rubbing machine, comprising a metal plate having spaced apart threaded studs secured thereto to project outwardly therefrom, a first sheet of rubber-like covering material on one face of said plate, said studs protruding through said sheet, a second sheet of rubber-like material on the other face of said plate, said sheets projecting beyond all edges of the plate, a pad of sponge rubber, a third sheet of rubber-like material vulcanized to the face and side and end edges of the pad, the edge portions of said third sheet projecting between the second sheet and the pad and vulcanized thereto, the projectin edge portions of the first and second sheets being vulcanized together outside of the plate perimeter.

13. A rubbing and polishing shoe adapted to be removably secured to a longitudinally recessed head plate of a rubbing machine, comprising, an attaching plate having elongated resilient side edges, a resilient pad secured to one side of said attaching plate, said side edges projecting beyond where the pad is secured to the attaching plate, whereby the resilient side edges;may be forced into recesses in the head plate to hold the shoe to the head plate as the head plate reciprocates.

14. A rubbing and polishing shoe adapted to be secured to a longitudinally recessed head plate 2 of a rubbing machine, comprising, a resilient rubber plate of substantial thickness, a resilient pad on one face of said rubber plate, a covering rubber sheet extending around the outer face and side and end edges of said pad, the edge portions of the rubber covering sheet extending between the pad and the rubber plate and being secured thereto, the side edges of the rubber plate projecting beyond where the pad is secured to the rubber plate to serve as gripping edges adapted to be inserted into recesses in the head plate, to hold the shoe to the head plate as the head plate reciprocates.

EDWARD G. PETERSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

